Semiconductor devices are used today in ever-increasing numbers in the daily life. Typically, such semiconductor devices are manufactured by many steps in the manufacturing process including structuring masks, depositing semiconductor or non-semiconductor layers, etching these layers, etc.
For example in the field of integrated pressure sensor devices, a sequence of process steps is typically applied which includes the deposition and structuring of an oxide layer on top of a silicon substrate. On top of the structured oxide layer, a poly-Si (polychrystalline silicon) is deposited. After structuring the poly-Si layer, the oxide layer acting as sacrificial layer is etched by a wet chemical etching step.
Recently, a new process, the so-called Venezia process, has been described to form silicon membranes within a silicon substrate. For this, a trench etching into a silicon substrate and a high temperature step in pure hydrogen are combined to form a monocrystalline silicon plate overlying a closed cavity inside the silicon substrate. However, as the silicon plate is directly connected to the silicon substrate, this technique cannot be easily used in pressure sensor applications due to parasitic effects resulting from the direct connection.